In the related art, an information terminal that includes a touch panel on a display surface of a display is widely used. A large-sized information terminal, such as 27-inch one or 32-inch one, is disposed horizontally on a top surface of a table or the like, and thus, there are merits that anyone out of many people around the table easily sees and operates a display. These merits enable the information terminal to be utilized for a business meeting, a business talk at a store, or education at school or at a museum.
Incidentally, in the information terminal, in general, secret information, such as a password or a personal identification number, is input to perform a user's authentication, and after the authentication pass, information that the user is only allowed to browse is output.
However, as a side effect of the merits of easily seeing the display surface, the information terminal with a large-sized external appearance has security problems in that a third person who has nothing to do with the information easily peeps the information, during operation.
Regarding the problems, examples of secret information inputs using a touch panel are the following technologies in the related art.
Technologies disclosed in JP-A-11-149454, JP-A-2004-70941, and JP-A-2008-226243 use a member, on which a plurality of discontinuous bottomed bores or through-holes, or notches or marks is provided, as an authentication key.
A user makes the authentication key member come into contact with a touch panel to input a coordinate of a bore on the authentication key member, and an information terminal compares the input coordinate with a pre-registered coordinate to perform authentication.
A technology disclosed in JP-A-2013-12057 uses a member of which 4×4, total 16 bores are opened on the front surface as an authentication key. A plurality of conductive pins is inserted into any bores out of the 16 bores, and when a user makes the front surface of the key come into contact with a touch panel, each pin is detected by the touch panel. Authentication is performed by checking that an insertion pattern of pins into the bores out of the 16 bores matches a pre-registered pattern.
When these technologies are used, without a risk of a peep by a third person, the secret information for the authentication can be safely input to the information terminal.
In addition, regarding an output of information from a display, a film that, when adhered to a display, causes visibility from any direction except for a specific direction to be remarkably decreased, that is, a so-called “peep-proof film”, is widely used. When the film is adhered, the information displayed on the display can be prevented from a peep by a third person.